/* ============================================
   Rajat Sarkar - Academic Portfolio
   Professional GitHub Pages Website
   ============================================ */

/* --- CSS Variables --- */
:root {
    --primary: #0a192f;
    --primary-light: #112240;
    --accent: #ff6b35;
    --accent-hover: #e85a2a;
    --accent-glow: rgba(255, 107, 53, 0.15);
    --teal: #64ffda;
    --text: #2d3748;
    --text-light: #718096;
    --text-lighter: #a0aec0;
    --bg: #ffffff;
    --bg-alt: #f7fafc;
    --bg-card: #ffffff;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.12);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font);
    color: var(--text);
    background: var(--bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--accent-hover);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* --- Section Base --- */
.section {
    padding: 100px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 0.5rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
}

.section-subtitle {
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    margin-top: 1rem;
    max-width: 600px;
}

/* =============================================
   NAVIGATION
   ============================================= */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    border-bottom-color: var(--border);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-logo {
    font-size: 1.6rem;
    font-weight: 900;
    color: var(--primary);
    letter-spacing: -1px;
}

.accent {
    color: var(--accent);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    color: var(--text);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
    background: var(--accent-glow);
}

.nav-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--accent);
    color: #fff !important;
    padding: 8px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: 8px;
    transition: var(--transition);
}

.nav-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(255, 107, 53, 0.3);
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.hamburger span {
    width: 24px;
    height: 2.5px;
    background: var(--primary);
    border-radius: 2px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* =============================================
   HERO SECTION
   ============================================= */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #0a192f 0%, #112240 50%, #1a365d 100%);
}

.hero-bg {
    position: absolute;
    inset: 0;
    opacity: 0.3;
}

#hero-canvas {
    width: 100%;
    height: 100%;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 1200px;
    margin: 0 auto;
    padding: 120px 24px 80px;
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: center;
}

.hero-greeting {
    color: var(--accent);
    font-family: var(--font-mono);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 12px;
    opacity: 0;
    animation: fadeInUp 0.6s 0.2s forwards;
}

.hero-name {
    font-size: 4.5rem;
    font-weight: 900;
    color: #fff;
    line-height: 1.1;
    letter-spacing: -2px;
    margin-bottom: 16px;
    opacity: 0;
    animation: fadeInUp 0.6s 0.4s forwards;
}

.hero-title-wrapper {
    display: flex;
    align-items: center;
    margin-bottom: 24px;
    min-height: 36px;
    opacity: 0;
    animation: fadeInUp 0.6s 0.6s forwards;
}

.hero-title {
    color: var(--teal);
    font-size: 1.4rem;
    font-weight: 600;
}

.cursor {
    color: var(--teal);
    font-size: 1.5rem;
    font-weight: 300;
    animation: blink 1s infinite;
    margin-left: 2px;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.hero-desc {
    color: #8892b0;
    font-size: 1.05rem;
    line-height: 1.8;
    max-width: 550px;
    margin-bottom: 32px;
    opacity: 0;
    animation: fadeInUp 0.6s 0.8s forwards;
}

.hero-desc strong {
    color: #ccd6f6;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 40px;
    opacity: 0;
    animation: fadeInUp 0.6s 1s forwards;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 107, 53, 0.3);
    color: #fff;
}

.btn-outline {
    background: transparent;
    color: var(--teal);
    border-color: var(--teal);
}

.btn-outline:hover {
    background: rgba(100, 255, 218, 0.1);
    color: var(--teal);
    transform: translateY(-2px);
}

.hero-social {
    display: flex;
    gap: 16px;
    opacity: 0;
    animation: fadeInUp 0.6s 1.2s forwards;
}

.hero-social a {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: 1.5px solid #233554;
    color: #8892b0;
    font-size: 1.1rem;
    transition: var(--transition);
}

.hero-social a:hover {
    color: var(--accent);
    border-color: var(--accent);
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(255, 107, 53, 0.2);
}

/* Profile Card */
.hero-visual {
    display: flex;
    justify-content: center;
    opacity: 0;
    animation: fadeInUp 0.8s 0.6s forwards;
}

.profile-card {
    background: rgba(17, 34, 64, 0.8);
    border: 1px solid rgba(100, 255, 218, 0.1);
    border-radius: var(--radius-lg);
    padding: 48px 40px;
    text-align: center;
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.profile-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent), var(--teal));
}

.profile-avatar {
    width: 140px;
    height: 140px;
    margin: 0 auto 24px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), #ff8f6b);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -1px;
    box-shadow: 0 8px 32px rgba(255, 107, 53, 0.3);
    overflow: hidden;
    padding: 3px;
}

.profile-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

.profile-stats {
    display: flex;
    gap: 24px;
    justify-content: center;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: #fff;
    line-height: 1;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.75rem;
    color: #8892b0;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: #8892b0;
    opacity: 0;
    animation: fadeInUp 0.6s 1.4s forwards;
}

.mouse {
    width: 24px;
    height: 38px;
    border: 2px solid #8892b0;
    border-radius: 12px;
    margin: 0 auto 8px;
    position: relative;
}

.wheel {
    width: 3px;
    height: 8px;
    background: #8892b0;
    border-radius: 2px;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0% { opacity: 1; transform: translateX(-50%) translateY(0); }
    100% { opacity: 0; transform: translateX(-50%) translateY(14px); }
}

.scroll-indicator p {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =============================================
   ABOUT SECTION
   ============================================= */
.about {
    background: var(--bg);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
}

.about-intro {
    font-size: 1.15rem;
    line-height: 1.8;
    margin-bottom: 1.2rem;
}

.about-text p {
    margin-bottom: 1rem;
    color: var(--text);
}

.about-text em {
    color: var(--accent);
    font-style: italic;
}

.research-interests {
    margin-top: 2rem;
}

.research-interests h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 12px;
}

.interest-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag {
    background: var(--accent-glow);
    color: var(--accent);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 0.82rem;
    font-weight: 600;
    border: 1px solid rgba(255, 107, 53, 0.2);
    transition: var(--transition);
}

.tag:hover {
    background: var(--accent);
    color: #fff;
    transform: translateY(-1px);
}

/* Timeline */
.timeline h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.timeline h3 i {
    color: var(--accent);
}

.timeline-item {
    position: relative;
    padding-left: 28px;
    padding-bottom: 24px;
    border-left: 2px solid var(--border);
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: -7px;
    top: 4px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid var(--bg);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.timeline-date {
    font-size: 0.78rem;
    color: var(--accent);
    font-weight: 600;
    font-family: var(--font-mono);
}

.timeline-content h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary);
    margin: 2px 0;
}

.timeline-content p {
    font-size: 0.88rem;
    color: var(--text-light);
    margin: 0;
}

.timeline-detail {
    font-size: 0.8rem;
    color: var(--text-lighter);
    font-style: italic;
}

/* Skills */
.skills-section {
    background: var(--bg-alt);
    border-radius: var(--radius-lg);
    padding: 40px;
    border: 1px solid var(--border);
}

.skills-section h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 24px;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.skill-category h4 {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.skill-category h4 i {
    color: var(--accent);
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.skill-items span {
    background: var(--bg);
    padding: 4px 12px;
    border-radius: 100px;
    font-size: 0.8rem;
    color: var(--text-light);
    border: 1px solid var(--border);
    font-weight: 500;
}

/* =============================================
   RESEARCH SECTION
   ============================================= */
.research {
    background: var(--bg-alt);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

a.research-card {
    color: inherit;
    display: block;
}

a.research-card:hover {
    color: inherit;
}

.research-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
}

.research-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.research-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(255, 107, 53, 0.2);
}

.card-image {
    position: relative;
    overflow: hidden;
    background: var(--primary);
    aspect-ratio: 16 / 9;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
}

.card-image img {
    max-height: 100%;
    width: auto;
    max-width: 100%;
    object-fit: contain;
    transition: transform 0.5s ease;
}

.research-card:hover .card-image img {
    transform: scale(1.05);
}

.card-overlay {
    position: absolute;
    top: 12px;
    right: 12px;
}

.card-venue {
    background: var(--accent);
    color: #fff;
    padding: 4px 12px;
    border-radius: 100px;
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.card-content {
    padding: 24px;
}

.card-content h3 {
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 4px;
}

.card-subtitle {
    font-size: 0.88rem;
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 12px;
    line-height: 1.4;
}

.card-desc {
    font-size: 0.9rem;
    color: var(--text);
    line-height: 1.7;
    margin-bottom: 16px;
}

.card-desc strong {
    color: var(--accent);
    font-weight: 600;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}

.card-tags span {
    background: var(--bg-alt);
    color: var(--text-light);
    padding: 3px 10px;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 600;
    border: 1px solid var(--border);
}

.card-links a {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent);
}

.card-links a:hover {
    text-decoration: underline;
}

/* Featured Research Card */
.research-card.featured {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    border: 2px solid rgba(255, 107, 53, 0.3);
    background: linear-gradient(135deg, #fffaf7, #ffffff);
}

.research-card.featured .card-image {
    aspect-ratio: auto;
    min-height: 280px;
}

.card-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent), #ff8f6b);
    color: #fff;
    padding: 4px 14px;
    border-radius: 100px;
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

/* Featured Publication */
.pub-item.featured-pub {
    background: linear-gradient(135deg, #fffaf7, #ffffff);
    border: 1px solid rgba(255, 107, 53, 0.2);
    border-radius: var(--radius-md);
    padding: 28px 24px;
    margin-bottom: 8px;
}

/* =============================================
   PUBLICATIONS SECTION
   ============================================= */
.publications {
    background: var(--bg);
}

.pub-list {
    max-width: 900px;
}

.pub-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 24px;
    padding: 28px 0;
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

.pub-item:last-child {
    border-bottom: none;
}

.pub-item:hover {
    background: var(--bg-alt);
    padding-left: 16px;
    margin-left: -16px;
    margin-right: -16px;
    padding-right: 16px;
    border-radius: var(--radius-md);
}

.pub-year {
    font-size: 1rem;
    font-weight: 800;
    color: var(--accent);
    font-family: var(--font-mono);
    padding-top: 4px;
}

.pub-details h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 6px;
    line-height: 1.4;
}

.pub-authors {
    font-size: 0.88rem;
    color: var(--text-light);
    margin-bottom: 6px;
}

.pub-authors strong {
    color: var(--text);
}

.pub-venue {
    font-size: 0.85rem;
    color: var(--text-light);
    display: flex;
    align-items: flex-start;
    gap: 6px;
}

.pub-venue i {
    color: var(--accent);
    margin-top: 3px;
    flex-shrink: 0;
}

.pub-venue strong {
    color: var(--accent);
}

.pub-links {
    margin-top: 8px;
    display: flex;
    gap: 16px;
}

.pub-links a {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--accent);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255, 107, 53, 0.3);
    transition: var(--transition);
}

.pub-links a:hover {
    background: var(--accent);
    color: #fff;
}

/* =============================================
   PATENTS SECTION
   ============================================= */
.patents {
    background: var(--bg-alt);
}

.patent-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.patent-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 28px;
    display: flex;
    gap: 20px;
    transition: var(--transition);
}

.patent-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: rgba(255, 107, 53, 0.2);
}

.patent-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: var(--accent-glow);
    color: var(--accent);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.patent-info h3 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.4;
    margin-bottom: 6px;
}

.patent-id {
    font-size: 0.8rem;
    color: var(--accent);
    font-family: var(--font-mono);
    font-weight: 500;
    margin-bottom: 6px;
}

.patent-inventors {
    font-size: 0.82rem;
    color: var(--text-light);
}

.patent-inventors strong {
    color: var(--text);
}

/* =============================================
   ACHIEVEMENTS BANNER
   ============================================= */
.achievements {
    background: linear-gradient(135deg, var(--primary) 0%, #1a365d 100%);
    padding: 60px 0;
}

.achievements-banner {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.achievement-item {
    display: flex;
    align-items: center;
    gap: 16px;
    color: #fff;
}

.achievement-item i {
    font-size: 2rem;
    color: var(--accent);
    flex-shrink: 0;
}

.achievement-item h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 2px;
}

.achievement-item p {
    font-size: 0.82rem;
    color: #8892b0;
}

/* =============================================
   CONTACT SECTION
   ============================================= */
.contact {
    background: var(--bg);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.contact-card {
    text-align: center;
    padding: 32px 24px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.contact-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: rgba(255, 107, 53, 0.3);
}

.contact-card i {
    font-size: 1.8rem;
    color: var(--accent);
    margin-bottom: 16px;
}

.contact-card h3 {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.contact-card a,
.contact-card p {
    font-size: 0.9rem;
    color: var(--text-light);
}

.contact-card a:hover {
    color: var(--accent);
}

.contact-cta {
    text-align: center;
}

.cta-links {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.cta-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
}

.cta-link:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 107, 53, 0.15);
}

.cta-link i {
    font-size: 1.1rem;
}

/* =============================================
   FOOTER
   ============================================= */
.footer {
    background: var(--primary);
    color: #8892b0;
    padding: 48px 0 24px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 24px;
    border-bottom: 1px solid #233554;
}

.footer-logo {
    font-size: 1.4rem;
    font-weight: 900;
    color: #fff;
    letter-spacing: -1px;
}

.footer-brand p {
    font-size: 0.85rem;
    margin-top: 4px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: 1px solid #233554;
    color: #8892b0;
    transition: var(--transition);
}

.footer-social a:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    font-size: 0.82rem;
}

/* =============================================
   ANIMATIONS
   ============================================= */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* =============================================
   RESPONSIVE DESIGN
   ============================================= */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-name {
        font-size: 3.5rem;
    }

    .hero-desc {
        margin: 0 auto 32px;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-social {
        justify-content: center;
    }

    .hero-title-wrapper {
        justify-content: center;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .research-grid {
        grid-template-columns: 1fr;
    }

    .research-card.featured {
        grid-template-columns: 1fr;
    }

    .patent-grid {
        grid-template-columns: 1fr;
    }

    .achievements-banner {
        grid-template-columns: repeat(2, 1fr);
    }

    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .section {
        padding: 70px 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 4px;
        border-bottom: 1px solid var(--border);
        transform: translateY(-120%);
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
    }

    .nav-menu.active {
        transform: translateY(0);
    }

    .nav-link {
        width: 100%;
        text-align: center;
        padding: 12px 16px;
    }

    .nav-btn {
        margin-left: 0;
        justify-content: center;
    }

    .hamburger {
        display: flex;
    }

    .hero-name {
        font-size: 2.5rem;
    }

    .hero-title {
        font-size: 1.1rem;
    }

    .hero-visual {
        display: none;
    }

    .hero-content {
        padding-top: 100px;
    }

    .pub-item {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

    .achievements-banner {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-name {
        font-size: 2rem;
        letter-spacing: -1px;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .cta-links {
        flex-direction: column;
        align-items: center;
    }

    .cta-link {
        width: 100%;
        justify-content: center;
    }
}

/* =============================================
   RESEARCH DETAIL PAGES
   ============================================= */

/* Detail Hero */
.detail-hero {
    background: linear-gradient(135deg, #0a192f 0%, #112240 50%, #1a365d 100%);
    padding: 140px 0 80px;
    position: relative;
    overflow: hidden;
}

.detail-hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 80px;
    background: linear-gradient(to top, var(--bg), transparent);
}

.detail-hero .container {
    position: relative;
    z-index: 2;
}

.detail-back {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: #8892b0;
    font-size: 0.88rem;
    font-weight: 500;
    margin-bottom: 24px;
    transition: var(--transition);
}

.detail-back:hover {
    color: var(--accent);
    transform: translateX(-4px);
}

.detail-venue {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    padding: 6px 18px;
    border-radius: 100px;
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 16px;
}

.detail-hero h1 {
    font-size: 2.8rem;
    font-weight: 900;
    color: #fff;
    line-height: 1.2;
    letter-spacing: -1px;
    margin-bottom: 8px;
    max-width: 800px;
}

.detail-subtitle {
    font-size: 1.15rem;
    color: #8892b0;
    font-style: italic;
    margin-bottom: 20px;
    max-width: 700px;
}

.detail-authors {
    color: #ccd6f6;
    font-size: 0.95rem;
    margin-bottom: 24px;
}

.detail-authors strong {
    color: var(--accent);
}

.detail-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.detail-link-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 24px;
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid;
}

.detail-link-btn.primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.detail-link-btn.primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(255, 107, 53, 0.3);
    color: #fff;
}

.detail-link-btn.secondary {
    background: transparent;
    color: var(--teal);
    border-color: var(--teal);
}

.detail-link-btn.secondary:hover {
    background: rgba(100, 255, 218, 0.1);
    color: var(--teal);
    transform: translateY(-2px);
}

/* Detail Body */
.detail-body {
    padding: 80px 0;
}

.detail-grid {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 60px;
    align-items: start;
}

/* Sidebar */
.detail-sidebar {
    position: sticky;
    top: 96px;
}

.sidebar-card {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 28px;
    margin-bottom: 24px;
}

.sidebar-card h3 {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-lighter);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 16px;
}

.sidebar-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.sidebar-tags .tag {
    font-size: 0.78rem;
    padding: 4px 12px;
}

.sidebar-meta {
    list-style: none;
}

.sidebar-meta li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.88rem;
    color: var(--text);
}

.sidebar-meta li:last-child {
    border-bottom: none;
}

.sidebar-meta li i {
    color: var(--accent);
    margin-top: 3px;
    width: 16px;
    flex-shrink: 0;
}

.sidebar-meta li span {
    color: var(--text-light);
}

/* Content Sections */
.detail-section {
    margin-bottom: 48px;
}

.detail-section h2 {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border);
}

.detail-section p {
    font-size: 1rem;
    line-height: 1.85;
    color: var(--text);
    margin-bottom: 16px;
}

.detail-section ul {
    margin: 12px 0 16px 20px;
    color: var(--text);
}

.detail-section li {
    margin-bottom: 8px;
    line-height: 1.7;
    font-size: 0.95rem;
}

.detail-section li strong {
    color: var(--accent);
}

/* Figure Container */
.figure-container {
    margin: 32px 0;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.figure-container img {
    width: 100%;
    display: block;
    padding: 20px;
    background: #fff;
}

.figure-container.dark-bg img {
    background: var(--primary);
    padding: 24px;
}

.figure-caption {
    padding: 12px 20px;
    font-size: 0.85rem;
    color: var(--text-light);
    border-top: 1px solid var(--border);
    font-style: italic;
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 24px 0;
}

.results-grid .figure-container {
    margin: 0;
}

/* Key Highlights */
.highlights-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin: 24px 0;
}

.highlight-card {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 24px;
    text-align: center;
    transition: var(--transition);
}

.highlight-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: rgba(255, 107, 53, 0.2);
}

.highlight-value {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--accent);
    display: block;
    margin-bottom: 4px;
}

.highlight-label {
    font-size: 0.82rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Responsive Detail */
@media (max-width: 1024px) {
    .detail-grid {
        grid-template-columns: 1fr;
    }

    .detail-sidebar {
        position: static;
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
}

@media (max-width: 768px) {
    .detail-hero h1 {
        font-size: 1.8rem;
    }

    .detail-sidebar {
        grid-template-columns: 1fr;
    }

    .results-grid {
        grid-template-columns: 1fr;
    }

    .highlights-grid {
        grid-template-columns: 1fr;
    }

    .detail-body {
        padding: 48px 0;
    }
}